The practice of writing works which falsely claimed to be translations began in medieval chivalric romance.
It was common in 16th-century Spain, where Amadís de Gaula and the numerous works descended from it benefited from the invention of printing to offer fantasies of travel, war, and love to wealthy young adults.
Cervantes wrote the 1605 Don Quixote to finish them off (he succeeded) because he believed that false history was socially harmful, as one of his characters explains in Chapter 49.
[1] The concept of a pseudotranslation was reinvented by Israeli scholar Gideon Toury in Descriptive Translation Studies–and Beyond (1995).
"[4] Scholars such as Gideon Toury also note that readers are more likely to accept texts that differ from the norm if they are culturally distant.